That's a good chunk. The biggest one I have ever got was about 1/10th of an ounce from Clear Creek California.
I was with a guy at the pay to pan area at Rich Bar on the Feather River about 10 years ago when he got a 3 ounce nugget out of a long seam in the rocks. It was shaped like a small golden egg and we flattened it on one side a little to make sure it was gold. One side had pick marks from the 49ers who had dug out the seam originally and hammered it farther back into the rear of the crack.